If I want to create new backlinks for my website, how much is considered to be too much for SE? 100? 1000?
It depends. If you have some content that hits the digg front page, 100 sites could qucikly pick it up. I guess it goes with consistency and starting small and building up naturally.
depends on how many backlinks you already have. for example, you already have: 500,000 then another 500 would be okay but if you have 500 then another 500 would probably be given the flag.
I think its better build 1k to 2k links per month.I recommend u to spread out the link building to a month.
It is not obvious that u had submit 100 directories than all will approve it. so submit your site or go for link building periodically. it matter that how many back links u have, as 123606 told. if u get thousands of link in one day than it may affect.
there is no limits for links per day, because the links you are adding today can be crawled today or may be after 10days by search engines. Make sure you get link from relevant website and that have some reputation.